Subgrade vault



FIG. 1 is a front perspective view of a subgrade vault showing our new design;

FIG. 2 is a front elevation view thereof;

FIG. 3 is a rear elevation view thereof;

FIG. 4 is a right side elevation view thereof;

FIG. 5 is a left side elevation view thereof;

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a bottom plan view thereof.

The broken lines showing portions of the subgrade vault are included for the purpose of illustrating environment and form no part of the claimed design. 

CLAIM The ornamental design for a subgrade vault, as shown and described. 